To develop more kinds of digital visual effects based on a selfie image, extracting the foreground human object from the selfie image is an essential technique. In general, the foreground human object is recognized from an image by some facial identification algorithms (e.g., edge detections, facial features detections, etc).
Currently, a mobile phone usually includes two cameras, which are a front camera and a back camera. The front camera is disposed on the same side with a display module and utilized mainly for selfie shooting, video-calling and some other photography functions related to the user. The back camera is disposed on the opposite side and utilized mainly for capturing an image of other people, landscapes or some background sceneries. When the user holds the mobile phones in a general case, the front camera faces toward to the user himself. If the foreground human object captured by the front camera could be extracted in real time, the foreground human object can be combined into another image for some visual effects or specific purposes. Moreover, if the foreground human object could be extracted in real time, the visual effect involving the foreground human object can be reflected on a user interface in real time, such that the user interface (about adjusting the visual effect) can be more straightforward and simple to manipulate.
However, it takes a certain computation time to extract the foreground human object from a background of the image. A delay time will exists in traditional procedures of extracting the foreground human object. Based on current identification algorithms, it is hard to extract the foreground human object in real time from the background. Therefore, the digital visual effects based on selfie images can not be reflected in real time.